package cn._42pay.simplepay.framework.util;

import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.Binarizer;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.DecodeHintType;
import com.google.zxing.EncodeHintType;
import com.google.zxing.LuminanceSource;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.Result;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import org.slf4j.LoggerFactory;

/**
 * @link https://blog.csdn.net/jinqilin721/article/details/78841028
 */
public final class QRCodeUtil extends LuminanceSource {

	private static final Logger logger = LoggerFactory.getLogger(QRCodeUtil.class);

	// 二维码颜色
	private static final int BLACK = 0xFF000000;
	// 二维码颜色
	private static final int WHITE = 0xFFFFFFFF;

	private final BufferedImage image;
	private final int left;
	private final int top;

	public QRCodeUtil(BufferedImage image) {
		this(image, 0, 0, image.getWidth(), image.getHeight());
	}

	public QRCodeUtil(BufferedImage image, int left, int top, int width, int height) {
		super(width, height);
		int sourceWidth = image.getWidth();
		int sourceHeight = image.getHeight();
		if (left + width > sourceWidth || top + height > sourceHeight) {
			throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
		}
		for (int y = top; y < top + height; y++) {
			for (int x = left; x < left + width; x++) {
				if ((image.getRGB(x, y) & 0xFF000000) == 0) {
					image.setRGB(x, y, 0xFFFFFFFF); // = white
				}
			}
		}
		this.image = new BufferedImage(sourceWidth, sourceHeight, BufferedImage.TYPE_BYTE_GRAY);
		this.image.getGraphics().drawImage(image, 0, 0, null);
		this.left = left;
		this.top = top;
	}

	@Override
	public byte[] getRow(int y, byte[] row) {
		if (y < 0 || y >= getHeight()) {
			throw new IllegalArgumentException("Requested row is outside the image: " + y);
		}
		int width = getWidth();
		if (row == null || row.length < width) {
			row = new byte[width];
		}
		image.getRaster().getDataElements(left, top + y, width, 1, row);
		return row;
	}

	@Override
	public byte[] getMatrix() {
		int width = getWidth();
		int height = getHeight();
		int area = width * height;
		byte[] matrix = new byte[area];
		image.getRaster().getDataElements(left, top, width, height, matrix);
		return matrix;
	}

	@Override
	public boolean isCropSupported() {
		return true;
	}

	@Override
	public LuminanceSource crop(int left, int top, int width, int height) {
		return new QRCodeUtil(image, this.left + left, this.top + top, width, height);
	}

	@Override
	public boolean isRotateSupported() {
		return true;
	}

	@Override
	public LuminanceSource rotateCounterClockwise() {
		int sourceWidth = image.getWidth();
		int sourceHeight = image.getHeight();
		AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0, 0.0, 0.0, sourceWidth);
		BufferedImage rotatedImage = new BufferedImage(sourceHeight, sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
		Graphics2D g = rotatedImage.createGraphics();
		g.drawImage(image, transform, null);
		g.dispose();
		int width = getWidth();
		return new QRCodeUtil(rotatedImage, top, sourceWidth - (left + width), getHeight(), width);
	}

	/**
	 * @param matrix
	 * @return
	 */
	private static BufferedImage toBufferedImage(BitMatrix matrix) {
		int width = matrix.getWidth();
		int height = matrix.getHeight();
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		for (int x = 0; x < width; x++) {
			for (int y = 0; y < height; y++) {
				image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
			}
		}
		return image;
	}

	/**
	 * 生成二维码图片
	 *
	 * @param matrix
	 * @param format
	 * @param file
	 * @throws IOException
	 */
	public static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
		BufferedImage image = toBufferedImage(matrix);
		if (!ImageIO.write(image, format, file)) {
			throw new IOException("Could not write an image of format " + format + " to " + file);
		}
	}

	/**
	 * 生成二维码图片流
	 *
	 * @param matrix
	 * @param format
	 * @param stream
	 * @throws IOException
	 */
	public static void writeToStream(BitMatrix matrix, String format, OutputStream stream) throws IOException {
		BufferedImage image = toBufferedImage(matrix);
		if (!ImageIO.write(image, format, stream)) {
			throw new IOException("Could not write an image of format " + format);
		}
	}

	/**
	 * 根据内容，生成指定宽高、指定格式的二维码图片
	 *
	 * @param text   内容
	 * @param width  宽
	 * @param height 高
	 * @param format 图片格式
	 * @return 生成的二维码图片路径
	 * @throws Exception
	 */
	private static String generateQRCode(String text, int width, int height, String format, String pathName)
			throws Exception {
		Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
		hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定编码格式
		hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级
		hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4
		BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
		File outputFile = new File(pathName);
		writeToFile(bitMatrix, format, outputFile);
		return pathName;
	}

	/**
	 * 输出二维码图片流
	 *
	 * @param text 二维码内容
	 * @param width 二维码宽
	 * @param height 二维码高
	 * @param format 图片格式eg: png, jpg, gif
	 * @param response HttpServletResponse
	 * @throws Exception
	 */
	public static void generateQRCode(String text, int width, int height, String format, HttpServletResponse response)
			throws Exception {
		Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
		hints.put(EncodeHintType.CHARACTER_SET, "utf-8");// 指定编码格式
		hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);// 指定纠错等级
		hints.put(EncodeHintType.MARGIN, 1); // 白边大小，取值范围0~4
		BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, width, height, hints);
		writeToStream(bitMatrix, format, response.getOutputStream());
	}

	/**
	 * 解析指定路径下的二维码图片
	 *
	 * @param filePath 二维码图片路径
	 * @return
	 */
	public static String parseQRCode(String filePath) {
		String content = "";
		try {
			File file = new File(filePath);
			BufferedImage image = ImageIO.read(file);
			LuminanceSource source = new QRCodeUtil(image);
			Binarizer binarizer = new HybridBinarizer(source);
			BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);
			Map<DecodeHintType, Object> hints = new HashMap<DecodeHintType, Object>();
			hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");
			MultiFormatReader formatReader = new MultiFormatReader();
			Result result = formatReader.decode(binaryBitmap, hints);

			logger.info("result 为：" + result.toString());
			logger.info("resultFormat 为：" + result.getBarcodeFormat());
			logger.info("resultText 为：" + result.getText());
			// 设置返回值
			content = result.getText();
		} catch (Exception e) {
			logger.error(e.getMessage());
		}
		return content;
	}

	public static void main(String[] args) {
		String text = "hello world!"; // 随机生成验证码
		System.out.println("随机码： " + text);
		int width = 100; // 二维码图片的宽
		int height = 100; // 二维码图片的高
		String format = "png"; // 二维码图片的格式

		try {
			// 生成二维码图片，并返回图片路径
			String pathName = generateQRCode(text, width, height, format, "D:/new.png");
			System.out.println("生成二维码的图片路径： " + pathName);

			String content = parseQRCode(pathName);
			System.out.println("解析出二维码的图片的内容为： " + content);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}
